Transmission electron microscopy (TEM) represents a high-precision electron microscopy technique capable of observing a structure of an atomic layer of a sample. In order to observe the atomic layer by means of the TEM, the sample needs to be manufactured to be thin, with a thickness of several nanometers (nm) so that electrons penetrate a cross section of the sample. Ion milling has been mainly used in the related art as such a method for manufacturing the sample, but the ion milling has many difficulties due to high price and damages to the sample. There is difficulty in lowering ion energy for the ion milling without damaging the sample and focusing an ion beam onto a very small sample.
Korean Patent Unexamined Publication No. 2003-0042958 (published date: Jun. 2, 2003) and Korean Patent Registration No. 10-0559245 (Publication date: Mar. 15, 2006) concern microsopy systems.